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Publication numberUS4953355 A
Publication typeGrant
Application numberUS 07/393,209
Publication dateSep 4, 1990
Filing dateAug 14, 1989
Priority dateAug 16, 1988
Fee statusLapsed
Also published asDE68902198D1, DE68902198T2, EP0355545A1, EP0355545B1
Publication number07393209, 393209, US 4953355 A, US 4953355A, US-A-4953355, US4953355 A, US4953355A
InventorsJean Poulain, Jacques Desdouits
Original AssigneeGec Alsthom Sa
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Steam turbine installation with adjusted bleeding
US 4953355 A
Abstract
A steam turbine installation with bleeding adjusted to a predetermined pressure P, the installation driving a load and including a bleed outlet disposed between two successive stages, wherein the bleed pressure P is adjusted over a range D of bleed rates by a servo valve disposed on the exhaust duct and controlled by a servo-control circuit including device for measuring the pressure of the bleed flow.
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Claims(3)
We claim:
1. In a steam turbine installation provided with means including a bleed line for bleeding the turbine installation to adjust the pressure in the bleed line to a predetermined pressure P, the installation driving a load and including a bleed outlet disposed between two successive stages and opening to said bleed line, the improvement comprising an exhaust duct, and a servo valve disposed on the exhaust duct and controlled by a servo-control circuit including means for measuring the pressure of the bleed flow within said bleed line for adjusting the servo valve disposed on the exhaust duct to adjust the bleed pressure P over a range D of bleed rates.
2. A steam turbine installation according to claim 1, comprising first and second distinct turbines, and wherein said bleed outlet is disposed between two successive stages of the first turbine and said servo valve is disposed on an exhaust duct from said first turbine.
3. A steam turbine installation according to claim 2, wherein said two turbines are cantilever mounted.
Description

The present invention relates to a steam turbine installation in which bleeding is adjusted to a determined pressure.

BACKGROUND OF THE INVENTION

Establishments having their own installation for producing electricity also desire to have steam at a determined pressure for use either for heating purpoes, or else for some industrial process.

In conventional turbine installations between bearings and having a large number of stages on a common shaft and in a single turbine, bleeding is performed as shown in the diagram of FIG. 1. Taking this figure as an example, it can be seen that bleeding takes place via an outlet S situated between the sixth stage P and the seventh stage Q, and that the adjusting valve R for maintaining the bleeding pressure constant is likewise situated between the sixth stage and the seventh stage.

This disposition is bulky and lengthens the turbine by a length equivalent to at least three stages, as can be seen in FIG. 1.

In addition, such a disposition is very rarely possible on a cantilevered multiple turbine installation.

SUMMARY OF THE INVENTION

The present invention thus provides a steam turbine installation with bleeding adjusted to a predetermined pressure P, the installation driving a load and including a bleed outlet disposed between two successive stages, wherein the bleed pressure P is adjusted over a range D of bleed rates by means of a servo valve disposed on the exhaust duct and controlled by a servo-control circuit including means for measuring the pressure of the bleed flow.

Advantageously, the turbine installation comprises two distinct turbines, with the bleed outlet being disposed between two successive stages of the first turbine and with the servo valve being disposed on the exhaust duct from said first turbine.

BRIEF DESCRIPTION OF THE DRAWINGS

Two embodiments of the invention are described by way of example with reference to the accompanying drawings, in which:

FIG. 1 shows a conventional steam turbine installation between bearings and driving an alternator, with bleeding taking place at an adjusted pressure in the conventional manner;

FIG. 2 is a schematic hydraulic diagram of a steam turbine installation between bearings in accordance with the invention; and

FIG. 3 is a schematic hydraulic diagram of a preferred steam turbine installation in accordance with the invention comprising two turbines in a cantilevered configuration.

DETAILED DESCRIPTION

With reference to FIG. 2, the installation shown comprises a steam turbine 1 mounted between two bearings 2 and 3. The turbine drives an alternator 4 via a stepdown gear box 5. A duct 6 including an admission valve 7 supplies steam to the turbine, and its exhaust is connected to a condenser 8 via a duct 9.

In the figure shown, the turbine has seven stages, and a bleed duct 10 runs fron an intermediate point in the turbine between its fifth stage and its sixth stage.

Bleeding is adjusted to a predetermined pressure P. In order to perform this adjustment over a given range D of bleed rates, the exhaust duct 9 is provided with a servo-controlled valve 11. This valve 11 is controlled by a servo-control circuit 12 including means for comparing a reference signal delivered by a set point generator 13 and a signal coming from a pressure sensor 14 situated in the bleed duct 10.

As can be seen, the invention makes it possible to physically separate the functions of bleeding and of adjusting the bleed pressure, thereby reducing the length of the turbine rotor.

FIG. 3 shows a particularly advantageous example of the invention as applied to a cantilevered multiple turbine installation. In FIG. 3, the installation shown comprises two steam turbines 20 and 21 which are cantilvered. The high pressure turbine 20 is connected to the low pressure turbine 21 by means of the high pressure turbine exhaust duct 22. The two turbines 21 and 22 are connected in parallel to inlets of a stepdown gear box 23 whose outlet shaft drives a load 24, e.g. an alternator. The low pressure turbine 21 exhausts into a condenser 25.

The high pressure turbine 20 is fed with steam from an admission duct 26 which is provided with an admission valve 33, with said steam being taken from a boiler. The bleed duct 27 runs from an intermediate point within the high pressure turbine 2 between two expansion stages therein, and in particular between the third stage and the fourth stage in the example shown. This bleeding is adjusted to a determined pressure P.

In order to perform this adjustment, over a given range D of bleed rates, the exhaust duct 22 from the first turbine 20 is provided with a servo-controlled valve 28. The valve 28 is controlled from a servo-control circuit 29 having means for comparing a reference signal delivered by a set point generator 30 with a signal delivered by a pressure sensor 31 situated in the bleed duct 27.

The installation shown also includes a second, nonadjusted bleed 32 taken downstream from the first stage in the low pressure turbine 21.

In general, the adjustment system 28 is a system including a plurality of valves feeding separate injection sectors.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1777470 *Apr 10, 1929Oct 7, 1930Westinghouse Electric & Mfg CoMultistage-bleeder-turbine control
US3724214 *Mar 5, 1971Apr 3, 1973Westinghouse Electric CorpExtraction control system for a turbogenerator set
US4087797 *Jul 19, 1976May 2, 1978Westinghouse Electric Corp.System for detecting water in steam pipes
US4324103 *Jan 22, 1979Apr 13, 1982Bbc Brown, Boveri & Company LimitedMethod and apparatus for regulating a steam turbine
EP0195326A1 *Mar 7, 1986Sep 24, 1986Hitachi, Ltd.A protection-driving method of a feedwater heater and the device thereof
GB2061555A * Title not available
Non-Patent Citations
Reference
1 *Patent Abstracts of Japan, vol. 8, No. 148, 11/1984; JP A 59 46 303 (Tokyo Shibaura Denki K.K.).
2Patent Abstracts of Japan, vol. 8, No. 148, 11/1984; JP-A-59 46-303 (Tokyo Shibaura Denki K.K.).
3 *Patent Abstracts of Japan, vol. 9, No. 22, 1/30/1985; JP A 59, 168 203 (Mitsubishi Jukogyo).
4Patent Abstracts of Japan, vol. 9, No. 22, 1/30/1985; JP-A-59, 168-203 (Mitsubishi Jukogyo).
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US7826728Jul 13, 2006Nov 2, 2010Olympus CorporationImage processing system and camera
EP1632650A1 *Sep 1, 2004Mar 8, 2006Siemens AktiengesellschaftSteam turbine
WO2006024597A1 *Aug 12, 2005Mar 9, 2006Siemens AgSteam turbine
Classifications
U.S. Classification60/663, 60/677, 60/678, 60/715
International ClassificationF01K7/34, F01D17/08, F01K7/38, F01D17/10
Cooperative ClassificationF01D17/105, F01K7/345, F01D17/08
European ClassificationF01D17/10B, F01D17/08, F01K7/34B
Legal Events
DateCodeEventDescription
Nov 15, 1994FPExpired due to failure to pay maintenance fee
Effective date: 19940907
Sep 4, 1994LAPSLapse for failure to pay maintenance fees
Apr 12, 1994REMIMaintenance fee reminder mailed
May 11, 1990ASAssignment
Owner name: GEC ALSTHOM SA, FRANCE
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:POULAIN, JEAN;DESDOUITS, JACQUES;REEL/FRAME:005294/0278
Effective date: 19890629